Compound semiconductor growth using ion implantation

ABSTRACT

A workpiece is implanted to affect growth of a compound semiconductor, such as GaN. Implanted regions of a workpiece increase, reduce, or prevent growth of this compound semiconductor. Combinations of implants may be performed to cause increased growth in certain regions of the workpiece, such as between regions where growth is reduced. Growth also may be reduced or prevented at the periphery of the workpiece.

CROSS-REFERENCE TO RELATED APPLICATIONS

This claims priority to the provisional patent application entitled“Improved Epitaxial Growth,” filed May 13, 2011 and assigned U.S. App.No. 61/486,032, the disclosure of which is hereby incorporated byreference.

FIELD

This invention relates to ion implantation and, more particularly, toion implantation to improve the quality of a layer grown on a workpiece.

BACKGROUND

Ion implantation is a standard technique for introducing material into aworkpiece. A desired implant material is ionized in an ion source, theions are accelerated to form an ion beam of prescribed energy, and theion beam is directed at the surface of the workpiece. The energetic ionsin the ion beam penetrate into the bulk of the workpiece material andaffect both the surface and depth of the workpiece material undercertain conditions.

Gallium nitride (GaN) is a material commonly grown on workpieces. GaN isbecoming more important for use in light-emitting diodes (LEDs), powertransistors, and solid state lasers. The ability to grow high-qualityGaN is one limiting factor to improving the quality and lowering thecost of these devices. One method of improving the quality ofepitaxially-grown GaN is known as epitaxial layer overgrowth (ELOG). ForELOG, a layer of GaN is grown, hard mask windows of SiO₂ or Si_(x)N_(y)are deposited, and then the high-quality GaN is grown. In someinstances, deposition of the hard mask requires removal of the workpiecefrom the MOCVD tool and then reintroduction of the workpiece to theMOCVD tool after a lithography step, photoresist application,deposition, and photoresist removal. This particular process iscumbersome and costly. Repeated ELOG sequences add even more cost.

FLOG of GaN on silicon, sapphire, SiC, AlN, GaN, or other workpieces canbe accomplished using implantation instead of SiO₂ or Si_(x)N_(y)deposition. Previously, photoresist was used to mask part of the siliconworkpiece and implantation was performed on the unmasked areas. GaN grewlaterally over the implanted areas. However, this process is stillfairly complex. The use of photoresist adds extra steps, which increasesmanufacturing costs. What is needed is a faster, less complex, and lowercost method of growing high-quality compound semiconductor layers.

SUMMARY

According to a first aspect of the invention, a method of workpieceprocessing is provided. The method comprises implanting a firstplurality of implanted regions in a workpiece with a first species. Acompound semiconductor is grown on the workpiece after the implanting.The compound semiconductor growth is reduced on the first plurality ofimplanted regions compared to between the first plurality of implantedregions. At least one device is formed between the first plurality ofimplanted regions.

According to a second aspect of the invention, a method of workpieceprocessing is provided. The method comprises implanting a secondplurality of regions in a workpiece. A compound semiconductor is grownon the workpiece after the implanting. The compound semiconductor growthis increased on the plurality of implanted regions compared to betweenthe plurality of implanted regions.

According to a third aspect of the invention, a method of workpieceprocessing is provided. The method comprises implanting a periphery of aworkpiece. A compound semiconductor is grown on the workpiece after theimplanting. The growth is reduced on the periphery.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present disclosure, reference is madeto the accompanying drawings, which are incorporated herein by referenceand in which:

FIG. 1 is a cross-sectional side view of a first embodiment ofimplantation into a workpiece;

FIG. 2 is a cross-sectional side view of a second embodiment ofimplantation into a workpiece;

FIG. 3 is a cross-sectional side view of a third embodiment ofimplantation into a workpiece;

FIG. 4 is a cross-sectional side view of a fourth embodiment ofimplantation into a workpiece;

FIG. 5 is a top perspective view of a fifth embodiment of implantationinto a workpiece;

FIG. 6 is a cross-sectional side view of a sixth embodiment ofimplantation into a workpiece;

FIG. 7 is a top perspective view of a seventh embodiment of an implantedworkpiece;

FIG. 8 is a cross-sectional side view of an eighth embodiment of animplanted workpiece;

FIG. 9 is a perspective view of a ninth embodiment of an implantedworkpiece;

FIG. 10 is a top perspective view of a tenth embodiment of an implantedworkpiece;

FIG. 11 is a block diagram of a plasma processing apparatus having aplasma sheath modifier; and

FIG. 12 is a side view of an embodiment of selective ion implantation.

DETAILED DESCRIPTION

The embodiments are described herein in connection with formation of acompound semiconductor such as GaN, but these embodiments also may beused with other III/V compound semiconductors, II/VI compoundsemiconductors, or other materials known to a person skilled in the art.While specific types of implanters are disclosed, other ion implantationsystems known to those skilled in the art that can focus an ion beam orthat can implant particular regions of a workpiece with or without amask on the workpiece may be used in the embodiments described herein.While LEDs are specifically disclosed, other devices also may benefitfrom the embodiments described herein. The workpieces herein may besilicon, sapphire, AlN, GaN, other compound semiconductors, or othermaterials and include a coating or other layers in some instances. Anyimplant dimensions are exemplary and other dimensions are possible.Thus, the invention is not limited to the specific embodiments describedbelow.

FIG. 1 is a cross-sectional side view of a first embodiment ofimplantation into a workpiece. In this embodiment, a blanket implant isperformed over the entire surface of the workpiece 100 using the ions102 (illustrated by the arrows). The implanted region 109 is formed inthe workpiece 100. The devices 104A-104C, which may be GaN or some othercompound semiconductor, are then grown on top of this workpiece 100after the implantation is completed. The devices 104A-104C are shownwith dotted lines in FIG. 1 because these devices 104A-104C were notformed prior to the blanket implant. These devices 104A-104C may have awidth 105 of approximately 300 μm in one embodiment, though thesedevices 104A-104C may be between 100 μm to 3000 μm in dimension. Ofcourse, other dimensions are possible. A distance 106 of approximately100 μm may separate each pair of devices 104A-104C in one instance. Thedistance 106 also may be between 10 μm to 300 μm or other distancesknown to those skilled in the art.

The blanket implant that forms the implanted region 109 improvescompound semiconductor growth, such as the growth of GaN. This blanketimplant can be combined with a selective or patterned implant, as seenseparately in other embodiments herein. The blanket implant andpatterned implants can be performed in either order. One possiblemechanism that causes the improved growth is that the implant changesthe stoichiometry on the surface of the workpiece 100 or relieves thelattice mismatch between the workpiece 100 and the compoundsemiconductor. Stoichiometry is changed by either adding particularelements through implantation or by preferential sputtering of theelements from the workpiece. For example, preferentially sputtering Alor O in a sapphire workpiece 100, depending on implant species, energy,angle, and dose, may affect the stoichiometry of the workpiece 100. Ofcourse, other mechanisms are possible.

FIG. 2 is a cross-sectional side view of a second embodiment ofimplantation into a workpiece. In this embodiment, the workpiece 100 isimplanted using ions 102 in the implanted regions 103A-103C. Devices104A-104C are formed on the implanted regions 103A-103C during a laterprocessing step. These devices 104A-104C may have a width 105 ofapproximately 300 μm and may be separated by a distance 106 ofapproximately 100 μm, though other dimensions are possible. A plasmaprocessing apparatus having a plasma sheath modifier, such as thatillustrated in FIGS. 11-12, or other systems may be used to perform thisselective implantation. Thus, parts of the workpiece 100 are notimplanted, such as the distance 106 between implanted regions 103A-103C.The implanted regions 103A-103C improve compound semiconductor growth onthe workpiece 100 or make the compound semiconductor grow at anincreased rate. Some compound semiconductor growth may occur between theimplanted regions 103A-103C in one instance, but it may occur at a rateless than the growth on the implanted regions 103A-103C.

FIG. 3 is a cross-sectional side view of a third embodiment ofimplantation into a workpiece. In this embodiment, only a portion of theareas under the devices 104A-104C are implanted. The ions 102 onlyimplant the implanted regions 110A-110F. Thus, these implanted regions110A-110F are smaller than a dimension of the devices 104A-104C. Forexample, the implanted regions 110A-110F may have a width 111 ofapproximately 20 μm while the devices 104A-104C may have a width 105 ofapproximately 300 μm, though other dimensions are possible. Again, aplasma processing apparatus having a plasma sheath modifier, such asthat illustrated in FIGS. 11-12, or other systems may be used to performthis selective implantation. Such a selective implantation may improveELOG and the subsequently-grown compound semiconductor may be of higherquality. This also may enable ELOG within a single device. The implantedregions 110A-110C can improve, reduce, or prevent compound semiconductorgrowth on the workpiece 100. Thus, the compound semiconductor growth maybe at a slower rate over the implanted regions 110A-110C in oneinstance.

One possible mechanism that reduces or prevents compound semiconductorgrowth is that the compound semiconductor will preferentially deposit ona crystalline portion of the workpiece 100 compared to an amorphousportion of the workpiece 100. An implant may cause amorphization of theworkpiece 100. Another possible mechanism that reduces or preventscompound semiconductor growth relates to using a species that interfereswith the nucleation of the compound semiconductor. F, Cl, C, or metalsmay have this effect. Of course, other mechanisms are possible.

FIG. 4 is a cross-sectional side view of a fourth embodiment ofimplantation into a workpiece. In this embodiment, a blanket implant ofthe entire workpiece 100 is performed, but a proximity mask 112positioned above or a distance from the workpiece 100 is used to block aportion of the ions 102. Thus, the apertures 113 in the proximity mask112 correspond with the desired implanted regions 103A-103C. The devices104A-104C may have a width 105 of approximately 300 μm and may beseparated by a distance 106 of approximately 100 μm, though otherdimensions are possible. The distance 106 may not correspond exactlywith the dimensions of the proximity mask 112 and the width 105 may notcorrespond exactly with the dimensions of the aperture 113 due to theangles of the ions 102. The implanted regions 103A-103C may correspondwith the location of the devices 104A-104C that are formed during laterprocessing steps. A beamline ion implanter, plasma doping implanter, orother plasma system may be used with the proximity mask 112.

FIG. 5 is a cross-sectional side view of a fifth embodiment ofimplantation into a workpiece. In this embodiment, the apertures 113 inthe proximity mask 112 are configured such that the ions 102 implantonly a portion of areas under the devices 104A-104C during the blanketimplant of the workpiece 100. Thus, these implanted regions 110A-110Fare smaller than a dimension of the devices 104A-104C. For example, theimplanted regions 110A-110F may have a width 111 of approximately 20 μmwhile the devices 104A-104C may have a width 105 of approximately 300μm, though other dimensions are possible. The width 111 may notcorrespond exactly with the dimensions of the aperture 113 due to theangles of the ions 102. A beamline ion implanter, plasma dopingimplanter, or other plasma system may be used with the proximity mask.

FIG. 6 is a cross-sectional side view of a sixth embodiment ofimplantation into a workpiece. In this embodiment, the regions betweenthe devices 104A-104C are implanted. Thus, the ions 102 form theimplanted regions 114A-114D. These implanted regions 114A-114D mayprevent or reduce GaN growth between the devices 104A-104C duringformation of these devices 104A-104C. While a patterned implant of theions 102 is illustrated, a proximity mask also may be used. This may becombined with a blanket implant (to increase or reduce GaN growth) orother embodiments disclosed herein. In one embodiment, the compoundsemiconductor is grown on the surface of the workpiece 100, but thisgrowth may be at a reduced rate over the implanted regions 114A-114Dcompared to between the implanted regions 114A-114D. In anotherembodiment, compound semiconductor growth over the implanted regions114A-114D is prevented but growth between the implanted regions114A-114D still occurs.

FIG. 7 is a top perspective view of a seventh embodiment of an implantedworkpiece. In this particular embodiment, multiple implant steps areperformed. First, a series of lines are implanted in the workpiece toform the implanted regions 115A-115D, which may be similar to theimplant illustrated in FIG. 6 that forms the implanted regions114A-114D. The workpiece 100 is then rotated, for example, 90° and asecond series of lines are implanted in the workpiece 100 to form theimplanted regions 116A-116D (which are shaded in FIG. 7). Of course,other rotation amounts, such as 60°, are possible. These implantedregions 115A-115D and implanted regions 116A-116D overlap. “Islands” or“blocks” (represented by the spaces 117) that may not be implanted aresurrounded by implanted “streets” (represented by the implanted regions115A-115D and implanted regions 116A-116D). The implanted regions115A-115D and implanted regions 116A-116D may prevent or reduce growthof the compound semiconductor. During compound semiconductor growth, thecrystal regions will meet within such a region 117, as represented bythe X within each region 117. While the X is illustrated, there may bevariation due to non-uniform deposition and the actual pattern of thecrystal regions may vary. The defects are reduced and localized in thecompound semiconductor, which leads to a higher quality layer of acompound semiconductor, such as GaN. The spaces 117 may have a dimension119 of approximately 100 to 500 μm. The implanted regions 115A-115D orimplanted regions 116A-116D may have a width 118 of approximately 10 to100 μm. Of course, other dimensions are possible.

In one particular embodiment, the whole surface of the workpiece 100 isimplanted. The implanted regions 115A-115D and implanted regions116A-116D may be implanted with, for example, Ar and the spaces 117 maybe implanted with, for example, N. Other embodiments or combination ofspecies is possible. This may be performed using either two or morepatterned implants or using a blanket implant (as illustrated in FIG. 1)to implant the spaces 117 with one or more patterned implant to form theimplanted regions 115A-115D and implanted regions 116A-116D. Forexample, a blanket N implant can be combined with two patterned Arimplants to form the structure shown in FIG. 7. The workpiece 100 isrotated between these two Ar implants.

The quality and growth rate of epitaxially-grown GaN on sapphire can tobe controlled by selection of the implant species. For example, N, Al,or O enhance GaN growth on sapphire while Ar prevents or reduces GaNgrowth on sapphire. Implanting Al, N, or O can change the stoichiometryon the surface of the sapphire workpiece. For example, if GaN is grownon a sapphire workpiece, the N implant will add N to the sapphireworkpiece surface. MN may have a better match to GaN than sapphire interms of lattice constant or size. Implanting Ar may change thestoichiometry by preferential sputtering of Al over the O on thesapphire surface, for example. High doses of some species, such as dosesabove 1E17 cm⁻² may prevent or reduce compound semiconductor growth ifamorphization occurs on the workpiece. Smaller ions, such as H or He,also may prevent or reduce compound semiconductor growth ifamorphization occurs. A dose smaller than 1E17 cm⁻² may be used toamorphize a workpiece and prevent or reduce compound semiconductorgrowth with other noble gases larger than Ar.

In one instance, two sapphire workpieces were implanted at 40 keV and1E17 cm⁻² using Ar and N, respectively. GaN successively grew on theN-implanted workpiece, while Ar caused pitting in the GaN growth. Thedose or either N or Ar may be optimized for improved GaN growth orreduction in growth. For example, an N dose below approximately 1E17cm⁻² may improve GaN growth. Of course, other species besides N or Armay be used. P, As, or other species also may enhance GaN growth. Othernoble gases, H, O, Al, C, or other species also may prevent or reduceGaN growth. For silicon workpieces, noble gases such as Ar, Xe, and Krmay prevent growth of GaN. O or N may form SiO₂ or SiN regions in asilicon workpiece during an anneal, which also may prevent growth ofGaN. These species also may have similar effects on other workpiecematerials or with other compound semiconductors.

Compound semiconductor growth, such as GaN growth, on a siliconworkpiece also may be enhanced by implanting C or Ge. This may form SiCor SiGe during an anneal. These SiC or SiGe regions modify the latticeparameter of the silicon and may allow better lattice matching to theGaN.

Effects on the surface of the workpiece also may enhance, reduce, orprevent growth of a compound semiconductor. For example, a 0.5 keV Arimplant into a silicon workpiece with a dose of 5E16 cm⁻² has been shownto sputter approximately 100 nm away from the workpiece. Thus, this isfurther increased when using a focused beam because the sputter yieldmay increase as the angle of incidence of the ions increases toward 60degrees. This may produce a textured workpiece. Besides the chemicaleffects from the ion implantation, this surface topography modificationalso may affect the growth of the compound semiconductor. In oneinstance, the textured surface caused by sputtering will enhancecompound semiconductor growth on the workpiece.

FIG. 8 is a cross-sectional side view of an eighth embodiment of animplanted workpiece. The workpiece 100, which also may include a blanketbuffer layer (not illustrated), is implanted using a proximity mask orpatterned implant as previously described. The implanted regions114A-114C and implanted regions 110A-110D are designed to reduce orprevent GaN growth. These implanted regions 114A-114C and implantedregions 110A-110D may be implanted with Ar. A compound semiconductor,such as GaN, is grown between these implanted areas to form devices 104Aand 104B, which may be LEDs. Defect lines or voids 120 form above theimplanted regions 110A-110D. These may encourage ELOG to occur withinthe individual devices 104A and 104B. Selective area growth (SAG) mayoccur between the devices 104A and 104B.

FIG. 9 is a perspective view of a ninth embodiment of an implantedworkpiece. This embodiment may correspond to the embodiment illustratedin FIG. 8. The workpiece 100 is implanted. The implanted regions 114, ofwhich only one is pointed out in FIG. 9, separate multiple spaces 117.The compound semiconductor preferentially grows in the spaces 117between the implanted regions 114 because the implanted regions 114 areconfigured to reduce or prevent growth of a compound semiconductor. Atleast one space 117 has at least one implanted regions 110, of whichonly one is pointed out in FIG. 9. The implanted regions 114 and 110 areconfigured to reduce or prevent growth of GaN. The spaces 117 may beimplanted in one instance to improve growth of GaN. Of course, otherimplant patterns are possible from that illustrated in FIG. 9.

FIG. 10 is a top perspective view of a tenth embodiment of an implantedworkpiece. The periphery 121 (shaded in FIG. 10) of the workpiece 100 isimplanted to reduce or prevent compound semiconductor growth. During agrowth process, GaN or another compound semiconductor may grow thickeror at a faster rate at this periphery 121 than in the center 122. Thelattice constant of, for example, GaN may be smaller than that of thesapphire or silicon in a workpiece 100. Thus, the GaN deposits undersignificant strain at the center 122 of the workpiece 100. At theperiphery 121 of the workpiece 100, the GaN deposits more freely or isless constrained and forms an initial layer more quickly. Once the GaNis deposited, additional Ga and N atoms deposit more freely on the GaNat the periphery 121 of the workpiece 100 than filling the center 122 ofthe workpiece 100. This forms a thicker outer layer of GaN on theworkpiece 100. This effect may disappear when a sufficiently thick layerof GaN, such as greater than approximately 100 nm, is formed on theentire surface of the workpiece 100, but the workpiece 100 may stillhave an uneven layer of GaN due to the initial GaN growth at theperiphery 121.

The resulting thicker GaN at the periphery 121 may lead to crackingbecause of the increased stresses caused by the difference in thickness.The implant at the periphery 121 is configured to reduce compoundsemiconductor growth so that this compound semiconductor growth is equalon both the periphery 121 and center 122. This results in a workpiece100 having a compound semiconductor layer with an approximately equal oruniform thickness. Or, alternatively, the implant at the periphery 121is configured to totally prevent compound semiconductor growth on theperiphery 121. In one particular embodiment, the workpiece 100 isrotated 360° under a fixed ion beam that: has a width of the implantedarea at the periphery 121. In one instance, the periphery 121 that isimplanted has a width of approximate 5 mm, though other dimensions arepossible. This implant into the periphery 121 may be combined with otherimplants, such as the resulting implanted workpiece 100 of FIG. 9.

In one particular embodiment, the workpieces may have a blanket implantperformed across the entire surface of the workpiece prior to thepatterned implant. This may be have a different dose, energy, or speciesfrom a patterned implant. The blanket implant may improve compoundsemiconductor growth.

In an alternate embodiment, the compound semiconductor may be grown in aplasma cluster tool. This may be the same tool where the implants wereperformed or it may be operatively linked to the tool where the implantswere performed. Vacuum may not be broken around the workpiece if thetools are operatively linked, which reduces oxide layers, contaminationof workpieces, and increases throughput. Ion beam assisted deposition(IBAD) also may assist in GaN growth.

FIG. 11 is a block diagram of a plasma processing apparatus having aplasma sheath modifier. The plasma 140 is generated as is known in theart. This plasma 140 is generally a quasi-neutral collection of ions andelectrons. The ions typically have a positive charge while the electronshave a negative charge. The plasma 140 may have an electric field of,for example, approximately 0 V/cm in the bulk of the plasma 140. In asystem containing the plasma 140, ions 102 from the plasma 140 areattracted toward a workpiece 100. These ions 102 may be attracted withsufficient energy to be implanted into the workpiece 100. The plasma 140is bounded by a region proximate the workpiece 100 referred to as aplasma sheath 242. The plasma sheath 242 is a region that has fewerelectrons than the plasma 140. Hence, the differences between thenegative and positive charges cause a sheath potential in the plasmasheath 242. The light emission from this plasma sheath 242 is lessintense than the plasma 140 because fewer electrons are present and,hence, few excitation-relaxation collisions occur. Thus, the plasmasheath 242 is sometimes referred to as “dark space.”

The plasma sheath modifier 101 is configured to modify an electric fieldwithin the plasma sheath 242 to control a shape of a boundary 241between the plasma 140 and the plasma sheath 242. Accordingly, ions 102that are attracted from the plasma 140 across the plasma sheath 242 maystrike the workpiece 100 at a large range of incident angles. Thisplasma sheath modifier 101 may be referred to as, for example, afocusing plate or sheath engineering plate.

In the embodiment of FIG. 11, the plasma sheath modifier 101 includes apair of panels 212 and 214 defining an aperture there between having ahorizontal spacing (G). The panels 212 and 214 may be an insulator,semiconductor, or conductor. In other embodiments, the plasma sheathmodifier 101 may include only one panel or more than two panels. Thepanels 212 and 214 may be a pair of sheets having a thin, flat shape. Inother embodiments, the panels 212 and 214 may be other shapes such astube-shaped, wedge-shaped, and/or have a beveled edge proximate theaperture. The panels 212 and 214 also may be positioned a verticalspacing (Z) above the plane 151 defined by the front surface of theworkpiece 100. In one embodiment, the vertical spacing (Z) may be about1.0 to 10.0 mm.

Ions 102 may be attracted from the plasma 140 across the plasma sheath242 by different mechanisms. In one instance, the workpiece 100 isbiased to attract ions 102 from the plasma 140 across the plasma sheath242. In another instance, a plasma source that generates the plasma 140and walls surrounding the plasma 140 are biased positively and theworkpiece 100 may be grounded. The biasing may be pulsed in oneparticular embodiment. In yet another instance, electric or magneticfields are used to attract ions 102 from the plasma 140 toward theworkpiece 100.

Advantageously, the plasma sheath modifier 101 modifies the electricfield within the plasma sheath 242 to control a shape of the boundary241 between the plasma 140 and the plasma sheath 242. The boundary 241between the plasma 140 and the plasma sheath 242 may have a convex shaperelative to the plane 151 in one instance. When the workpiece 100 isbiased, for example, the ions 102 are attracted across the plasma sheath242 through the aperture between the panels 212 and 214 at a large rangeof incident angles. For instance, ions 102 following trajectory path 271may strike the workpiece 100 at an angle of ±θ° relative to the plane151. Ions 102 following trajectory path 270 may strike the workpiece 100at about an angle of 0° relative to the same plane 151. Ions 102following trajectory path 269 may strike the workpiece 100 an angle of−θ° relative to the plane 151. Accordingly, the range of incident anglesmay be between +θ° and −θ° centered about 0°. In addition, some iontrajectories paths such as paths 269 and 271 may cross each other.Depending on a number of factors including, but not limited to, thehorizontal spacing (G) between the panels 212 and 214, the verticalspacing (Z) of the panels 212 and 214 above the plane 151, thedielectric constant of the panels 212 and 214, or other processparameters of the plasma 140, the range of incident angles (θ) may bebetween +60° and −60° centered about 0°.

FIG. 12 is a side view of an embodiment of selective ion implantation.Implanted regions 103 are formed in the workpiece 100 using the ions102. The workpiece 100 is scanned with respect to the plasma sheathmodifier 101 or ions 102, as illustrated by the arrow 108. This mayinvolve moving the plasma sheath modifier 101, workpiece 100, or both.The scanning may be in one dimension or two dimensions. In oneparticular embodiment, the workpiece 100 is biased when the ions 102implant the implanted regions 103. The bias scheme is adjusted toproduce the desired pattern of implanted regions 103. Thus, theworkpiece 100 is not biased when the ions 102 would implant between theimplanted regions 103. This eliminates or reduces ions 102 fromimpacting between the implanted regions 103. In this manner, theimplanted regions 103 may be formed without a mask or photoresist layeron the workpiece 100. Alignment, lithography, or photoresist removalsteps may be eliminated.

The location of the implanted regions 103 may be carefully controlledbecause spacing of the implanted regions 103 may affect growth of theGaN or another compound semiconductor during ELOG. This spacing may beoptimized for the improved compound semiconductor growth.

The dose rate and focus of the ions 102 can be varied to form theimplanted regions 103. If the workpiece 100 is scanned, then the ions102 may be switched on and off to form the implanted regions 103, thedose of the ion 102 may be adjusted to reduce implantation between theimplanted regions 103, or the ions 102 may be focused when implantingthe implanted regions 103. If the ions 102 are focused when implantingthe implanted regions 103, the ions 102 may be less focused over otherparts of the workpiece 100, which reduces implantation between theimplanted regions 103.

The present disclosure is not to be limited in scope by the specificembodiments described herein. Indeed, other various embodiments of andmodifications to the present disclosure, in addition to those describedherein, will be apparent to those of ordinary skill in the art from theforegoing description and accompanying drawings. These other embodimentsand modifications ions are intended to fall within the scope of thepresent disclosure. Furthermore, although the present disclosure hasbeen described herein in the context of a particular implementation in aparticular environment for a particular purpose, those of ordinary skillin the art will recognize that its usefulness is not limited thereto andthat the present disclosure may be beneficially implemented in anynumber of environments for any number of purposes. Accordingly, theclaims set forth below should be construed in view of the full breadthand spirit of the present disclosure as described herein.

1. A method of workpiece processing comprising: implanting a firstplurality of implanted regions in a workpiece with a first species; andgrowing a compound semiconductor on said workpiece after saidimplanting, wherein said compound semiconductor growth is reduced onsaid first plurality of implanted regions compared to between said firstplurality of implanted regions, wherein at least one device is formedbetween said first plurality of implanted regions.
 2. The method ofclaim 1, wherein said first plurality of implanted regions form a gridand said compound semiconductor grows preferentially in spaces betweensaid first plurality of implanted regions.
 3. The method of claim 1,further comprising implanting a second plurality of implanted regions insaid workpiece, wherein each of said second plurality of implantedregions is between said first plurality of implanted regions.
 4. Themethod of claim 1, further comprising implanting a periphery of saidworkpiece, wherein said growing is reduced on said periphery.
 5. Themethod of claim 4, wherein said growing is reduced to zero on saidperiphery.
 6. A method of workpiece processing comprising: implanting aplurality of implanted regions in a workpiece; and growing a compoundsemiconductor on said workpiece after said implanting, wherein saidcompound semiconductor growth is increased on said plurality ofimplanted regions compared to between said plurality of implantedregions.
 7. The method of claim 6, wherein further comprising implantinga second plurality of implanted regions in said workpiece, wherein eachof said plurality of implanted regions is between said second pluralityof implanted regions.
 8. The method of claim 7, wherein said secondplurality of implanted regions form a grid and said compoundsemiconductor grows preferentially on said plurality of implantedregions between said second plurality of implanted regions.
 9. Themethod of claim 6, further comprising implanting a periphery of saidworkpiece, wherein said growing is reduced on said periphery.
 10. Themethod of claim 9, wherein said growing is reduced to zero on saidperiphery.
 11. The method of claim 6, wherein said implanting textures asurface of said workpiece on said plurality of implanted regions.
 12. Amethod of workpiece processing comprising: implanting a periphery of aworkpiece; and growing a compound semiconductor on said workpiece aftersaid implanting, wherein said growing is reduced on said periphery. 13.The method of claim 12, wherein said growing is reduced to zero on saidperiphery.
 14. The method of claim 12, wherein said growing on saidperiphery is reduced to be approximately equal to growing at a center ofsaid workpiece whereby a thickness of said compound semiconductor isapproximately equal across said workpiece.
 15. The method of claim 12,wherein said implanting comprises rotating said workpiece with respectto an ion beam during said implanting, whereby said ion beam onlyimplants said periphery.
 16. The method of claim 12, wherein furthercomprising implanting a first plurality of regions in said workpiece,wherein said compound semiconductor growth is reduced on said firstplurality of implanted regions compared to between said first pluralityof implanted regions.
 17. The method of claim 16, wherein said firstplurality of regions form a grid and said compound semiconductor growspreferentially in spaces between said first plurality of regions. 18.The method of claim 16, further comprising implanting a second pluralityof regions in said workpiece, wherein each of said second plurality ofregions is between said first plurality of regions.